Aerodynamical and aeroelastic investigations of a riblet design appllied on the surface of turbine exit guide vanes of a low pressure turbine

The present work gives a closer insight into the aerodynamic parameters obtained for turbine exit guide vanes (TEGV) of a low pressure turbine (LPT) with riblets applied on their suction side. Experimental data was obtained by using an aerodynamic five-hole-probe including a thermocouple as well as a trailing edge probe. Additionally, a comparison between the flow fields of the experimental data and the numerical results, obtained by performing a steady state Reynolds-Averaged Navier-Stokes (RANS) simulation, was done. The investigated flow fields are located up- and downstream of the TEGV’s and show a good overall agreement. Additionally, aeroelastic investigations show an influence of the changed surface structure onto the vibrations of the upstream located rotor blades. For a visual examination of the flow field, oil flow visualizations are performed and compared with results obtained by CFD simulations.